17-hydroxy-7-(lower alkoxy)carbonyl-3-oxo-17alpha-pregn-4-ene-21-carboxylic acid ypsilon-lactones and congeners

ABSTRACT

PREPARATION AND VALUABLE BIOLOGICAL PROPERTIES-ESPECIALLY DIURETIC ACTIVITY-OF 17-HYDROXY-7-(LOWER ALKOXY)CARBONYL-3-OXO-17A-PREGN-4-ENE-21-CARBOXYLIC ACID Y-LACTONES, HYDROXY ACIDS AND THEIR SALTS CORRESPONDING THERETO, AND $1 AND THIO ESTER ANALOGS OF THESE LACTONES, ACIDS, AND SALTS ARE DICLOSED.

United States Patent 17-HYDROXY 7 (LOWER ALKOXY)CARBONYL- 3-0X0-17u-PREGN-4-ENE-Zl-CARBOXYLIC ACID 'y-LACTONES AND CONGENERS Richard M. Weier, Deerfieid, Ill., assignor to G. D. Searle & Co., Chicago, Ill.

No Drawing. Continuation-impart of application Ser. No. 174,922, Aug. 25, 1971. This application Oct. 2, 1972, Ser. No. 294,379

Int. Cl. C07c 173/00 US. Cl. 260-23957 21 Claims ABSTRACT OF THE DISCLOSURE Preparation and valuable biological propertiesespecially diuretic activity-of 17'hydroxy 7 (lower alkoxy)carbonyl-3-oXo17a-pregn 4 ene-21-carboxylic acid 'y-lactones, hydroxy acids and their salts corresponding thereto, and A and thio ester analogs of these lactones, acids, and salts are disclosed This application is a continuation-in-part of my copending application Ser. No. 174,922 filed Aug. 25, 1971.

This invention relates to l7-hydroxy-7-(lower alkoxy) carbonyl-3-oxo-17a-pregn-4-ene-2l-carboxylic acid -lactones and congeners. More particularly, this invention provides new, useful, and unobvious chemical compounds of the formulas H36 L H30 3 and (II) HaC HsC i U XZ wherein X represents oxygen or sulfur; Z represents hydrogen, alkali metal, alkaline-earth metal/2, ammonium, or alkyl except when X represents sulfur, in which circumstance Z represents solely alkyl; Z represents hydrogen, alkali metal, alkaline-earth metal/2, or ammonium; the dotted line signifies that the compounds can be either A or A; and the wavy line signifies that the 7-carbonyl substituent can be in either alpha or beta configuration. Those skilled in the art will recognize that the term alkaline-earth metal/2 is dictated by the fact that such metals are divalent, whereas the other substituents represented by Z and Z are monovalent; and when, for ex- 3,787,396 Patented fin. 22, 1974 ample, Z represents 021/ 2 in Formula I, the contemplated salts are more conventionally depicted thus n -2n+1 wherein n represents an integer less than 8.

Equivalent to the enformulated compounds for the purposes of this invention are solvates thereof in which biologically insignificant amounts of solvent are present.

The foregoing compounds are useful by reason of their valuable biological properties. Thus, for example, they are diuretic: They reverse the effect of desoxycortico sterone acetate (DCA) on urinary sodium and potassium.

The capacity of the instant compounds to reverse the renal electrolyte effects of DCA is evident from the results of a standardized test for this property carried out in rats substantially as described by C. M. Kagawa in chapter 34 of volume II of Evaluation of Drug Activities: Pharmacometrics, by D. R. Laurence and A. L. Bacharach. Details of such testing are described in US. Pat. 3,422,096.

Those skilled in the art will recognize that observations of activity in standardized tests for particular biological effects are fundamental to the development of valuable new drug products, both veterinary and human.

Preparation of the compounds of this invention proceeds by heating 17-hydroxy-3-oxo-17a-pregna-4,6-diene- 21-carboxylic acid 'y-lactone with potassium cyanide in aqueous methanol buffered by ethyl acetate to produce 7u,4-aminomethylidyne-5-cyano 17 hydroxy-3-oxo-Sfl, 17u-pregnane-2l-carboxylic acid 'y-lactone, which is heated with hydrochloric acid to afford 4a,7u-carbonyl- S-cyano-17-hydroxy-3-oxo-5B,17a-pregnane 21 carboxylic acid -lactone. From the latter compound, on heating with sodium metal and an alkanol of the formula wherein n is defined as before, and subsequent acidification with 10% hydrochloric acid, the corresponding 17- hydroxy-17a-(lower alkoxy)carbonyl-3-oxo-17u-pregn-4- ene 21 carboxylic acid -lactone and 17-hydroxy-7fl- (lower alkoxy)carbony1-3-oxo-17u-pregn 4 ene-21-carboxylic acid 'y-lactone, separable by fractional crystallization and chromatography on dry silica gel, are obtained. These epimers are converted to other 7u-carbonyl and 7/8-carbonyl epimers of the invention as set forth in the following 6 paragraphs and illustrated by Example 2 et seq. herein, configuration at carbon atom number 7 3 of the described products being identical with that of the starting materials in each instance.

Warming 2. 17-hydroxy-7-(lower alkoxy)carbonyl-3- oxo-l7a-pregn-4-ene-2l-carboxylic acid 'y-lactone with 1 equivalent of an alkali metal hydroxide in methanol affords the corresponding alkali metal l7-hydroxy-7-(lower alkoxy)carbonyl-3-oxo 17a pregn-4-ene-2l-carboxylate, which on brief contact with excess very dilute hydrochloric acid yields the corresponding 17-hydroxy-7-(lower alkoxy) carbonyl-3-oxo 17oz pregn-4-ene-21-carboxylic acid. Warming one of the latter acids with 1 equivalent of an alkaline-earth metal hydroxide in methanol or maintaining prolonged contact between the acid and excess ammonia dissolved q.s. saturation in 2-propanol affords the corresponding alkaline-earth metal or ammonium 17- hydroxy-7-(lower alkoxy) carbonyl-3-oxo 17a. pregn-4- ene-Zl-carboxylate, respectively.

By heating a 17-hydroxy-7-(1ower alkoxy)carbonyl- 3-oxo-l7a-pregn-4-ene-2l-carboxylic acid 'y-lactone with excess aqueous methanolic potassium hydroxide under nitrogen and subsequent acidification with hydrochloric acid, the corresponding l7-hydroxy-3-oxo-17a-pregn-4- ene-7,2l-dicarboxylic acid 'y-lactone results. Conversion thereof to the corresponding alkali metal 2l-carboxy-17- hydroxy-3-oxo-17a-pregn-4-ene-7-carboxylate 'y-lactone is achieved by prolonged contact at room temperatures under nitrogen with 1 equivalent of an alkali metal bicarbonate in aqueous'methanol, whereas the corresponding alkaline earth metal 2l-carboxy-17-hydroxy-3-oxo-17apregn-4-ene-7-carboxylate 'y-lactone eventuates from a 17- hydroxy-3-oxo-l7a-pregn-4-ene-7,2l-dicarboxylic acid 1- lactone by warming it with 1 equivalent of an alkalineearth metal hydroxide in 2-propanol under nitrogen. The same procedure adapted to preparing an ammonium 17- hydroxy-I-(lower alkoxy)carbonyl-3-oxo-l7a-pregn-4-ene- 2l-carboxylate from the corresponding 2l-carboxylic acid *y-lactone serves for the preparation of an ammonium 21 carboxy-l7-hydroxy-3-oxo-17a-pregn-4-ene-7-carboxylate from the corresponding l7-hydroxy-3-oxo-17a-pregn- 4-ene-7,21-dicarboxylic acid 'y-lactone.

Heating a 17-hydroxy-3-oxo-17u-pregn-4-ene-7,21-dicarboxylic acid 'y-lactone with 2 equivalents of aqueous alkali metal hydroxide alfords the corresponding di(alkali metal) l7-hydroxy 3-oxo-17a-pregn-4-ene-7,2l-dicarboxylate, which in turn is briefly contacted with excess, very dilute hydrochloric acid to produce the corresponding 17 hydroxy-3-oxo-17u-pregn-4-ene-7,2l-dicarboxylic acid. Warming one of the later acids with 2 equivalents of an alkaline-earth metal hydroxide in methanol or maintaining prolonged contact between the acid and excess ammonia dissolved q.s. saturation in 2-propanol affords the corresponding di(alkaline-earth metal or ammonium) 17-hydroxy-3-oxo-l7a-pregn-4-ene-7,2l-dicarboxylate, respectively.

An alternative method of preparing a 17-hydroxy-7- (lower alkoxy)carbonyl-3-oxo-17a-pregn-4-ene-2l-carbox ylic acid *y-lactone of this invention is to contact a 17- hydroxy-3-oxo-l7a-pregn-4-ene-7,2l-dicarboxylic acid 7- lactone with isobutyl chloroformate in cold tetrahydrofuran containing 4-methylmorpholine under nitrogen, thereby producing the anhydride of 17-hydroxy-3-oxo- 17a-pregn-4-ene-7,2l-dicarboxylic acid 'y-lactone with isobutoxyformic acid, then heat the anhydride under nitrogen with an alkanol of the formula wherein n is defined as before. It is not essential that the intermediate anhydride be isolated, although this is frequently preferable.

Upon consecutive and prolonged admixture, in chloroform containing triethylamine at room temperatures or below, of (l) ethyl chloroformate and (2) an alkanethiol of the formula n zn+1 wherein n is defined as before, followed by acidification with dilute hydrochloric acid, a 17-hydroxy-3-ox0-l7e pregn-4-ene-7,2l-dicarboxylic acid 'y-lactone is converted to the corresponding 17-hydroxy-7-(lower alkyl)thiocarbonyl-3-oxo-17a-pregn-4-ene-2l-carboxylic acid 'y-lactone.

By heating a 17-hydroxy-7-(lower alkoxy)carbonyl-3- oxo-l7a-pregn-4-ene-2l-carboxylic acid 'y-lactone with dichlorodicyanobenzoquinone in benzene under nitrogen, the corresponding 17-hydroxy-7-(lower alkoxy)carbonyl- 3-oxo-17a-pregna-1,4-diene-21-carboxylic acid -lactone is prepared, from which the A counterparts of the A compounds whose preparation is described in the preceding 5 paragraphs and illustrated by Examples 2-10 and 15-24 herein are available by analogous procedures.

The following examples describe in detail compounds illustrative of the present invention and methods which have been devised for their preparation. It will be apparent to those skilled in the art that many modifications, both of materials and of methods, may be practiced without departing from the purpose and intent of this disclosure. Throughout the examples hereinafter set forth, temperatures are given in degrees centigrade and relative amounts of materials in parts by weight, except as otherwise noted. Specific rotations refer to the D line of sodium, the solvent being chloroform at room temperature unless otherwise indicated.

EXAMPLE 1 (A) 7a,4-aminomethylidyne-5-cyano-l7-hydroxy-3-oxo- 5B,l7a-pregnane-2l-carboxylic acid -lactone A solution consisting of approximately 51 parts of 17-hydroxy-3-oxo-17a-pregna-4,6-diene 21 carboxylic acid -lactone, 50 parts of potassium cyanide, 72 parts of ethyl acetate, 454 parts of methanol, and 160 parts of water is heated at the boiling point under reflux with stirring for 4 /2 hours, then allowed to stand at room temperatures overnight. Organic solvents are thereupon removed by vacuum distillation, the oily residue is diluted with 500 parts of water, and the pH is adjusted to 7 by slowly introducing 20% hydrochloric acid. Hydrogen cyanide is evolved, and precipitation occurs. The precipitate is filtered oil, dried in air, and taken up in ethyl acetate. The ethyl acetate solution is extracted with 20% hydrochloric acid, and residual ethyl acetate is removed from the extract by bubbling nitrogen therethrough. The extract is thereupon cooled to 0 and neutralized with sodium hydroxide. The resultant tan precipitate is filtered off, washed well with water, dried in air, and recrystallized from acetone to give 7a,4-aminomethylidyne-5- cyano-17-hydroxy-3-oxo-5B,17a pregnane-Zl-carboxylic acid -lactone melting at 278-283". The product has the formula (B) 4a,7a-carbonyl-5-cyano-17-hydroxy-3-oxo-5B,l7apregnane-Zl-carboxylic acid w-lactone A slurry of approximately 21 parts of 7u,4-amin0 methylidyne 5 cyano-l7-hydroxy-3-oxo-5 s,l7u-pregnane-21-carboxylic acid -lactone in 350 parts of 3% hydrochloric acid is heated at 95 with occasional stirring for 4 hours, then cooled. Insoluble solids are separated by filtration, washed to neutrality with water,

dried in air, and recrystallized from Z-propanol to give 401,70: carbonyl-S-cyano-l7-hydroxy-3-oxo-Sp,17a-pregnane-21-carboxylic acid -lactone melting at 284-289. The product has the formula (C) 17-hydroxy-7a-methoxycarbonyl-3-oxo-17a-pregn- 4-ene-21-carboxylic acid 'y-lactone and 7B-epimer To 185 parts of sodium metal is added 4200 parts of methanol at a rate such that rapid refluxing is maintained. When the addition is complete, refluxing is continued for 3 hours via external heating, whereupon 14,200 parts of methanol followed by 197 parts of 4a,7a-carbonyl-5- cyano-l7-hydroxy-3-oxo-5B,17a pregnane-Zl-carboxylic acid 'y-lactone is introduced. The resultant solution is heated at the boiling point under reflux with stirring in a nitrogen atmosphere for 22 hours, whereupon solvent is removed by vacuum distillation. The oily residue is taken up in 4000 parts of water. The aqueous solution is diluted with 4000 parts of acetone and then acidified with 10% hydrochloric acid. After 30 minutes, the acetone is removed by vacuum distillation; and the residue is extracted with ethyl acetate. The extract is washed well with aqueous 5% potassium bicarbonate and then with water, next dried over magnesium sulfate and sodium sulfate, and finally stripped of solvent by vacuum distillation. The resultant oil is dissolved in a minimum amount of methanol. Colorless 17-hydroxy-7a-methoxycarbonyl-3-oxo-17a-pregn-4-ene-2l-carboxylic acid 7- lactone crystallizes out of the methanol solution and is isolated by filtration and dried in air. It melts at 190- 192'.

The mother liquor is chromatographed on silica gel, using benzene and mixtures thereof with increasing amounts of ethyl acetate as developing solvents. From an eluate comprising ethyl acetate in benzene, on evaporation of solvent and recrystallization of the residue from methanol, 17-hydroxy-7B-methoxycarbony1-3 oxo-17a-pregn-4-ene-2l-carboxylic acid 'y-lactone melting at 238-240 is obtained. This product has the formula mo l 0 C O OCH;

EXAMPLE 2 Potassium 17-hydroxy-7u-methoxycarbonyl-3-oxo-17apregn-4-ene-2l-carboxylate dihydrate and 135 parts of aqueous 4% potassium hydroxide in 2000 parts of methanol, protected by a nitrogen atmosphere, is warmed to 40 during 5 minutes and thereafter stirred at ambient temperatures overnight. The solution is thereupon heated at the boiling point under reflux for 2 hours, at which point solvent is removed by vacuum distillation and the residue taken up in 3000 parts of water. The solution thus obtained is washed well with ethyl acetate and then distilled to dryness leaving a gummy residue which is taken up in a minimum amount of ethanol. Suflicient ethyl acetate is added to precipitate potassium 17 hydroxy-7a-methoxy-carbonyl-S-oxo-17apregn-4-ene21-carboxylate dihydrate as a white flocculent solid. Water of crystallization is removed by heating in vacuo at around The dihydrate has the formula '"CHiCHiC 0 OK --G O OCH: -2H2O EXAMPLE 3 l7-hydroxy-7a-methoxycarbonyl-3-oxo-17u-pregn- 4-ene-21-carboxylic acid O --COOCH:

EXAMPLE 4 17-hydroxy-3-oxo-17a-pregn-4-ene-7a,2 l-dicarboxylic acid 'y-lactone A solution of approximately 1 part of 17-hydroxy-7u methoxycarbonyl 3 oxo-l7a-pregn-4-ene-2l-carboxylic acid 'y-lactone and 12 parts of aqueous 5% potassium hydroxide in 8 parts of methanol is heated at the boiling point under reflux in a nitrogen atmosphere for 6 hours, whereupon methanol is removed by vacuum distillation and the aqueous residue is diluted with 25 parts of acetone. The resultant mixture is acidified with 3% hydrochloric acid, allowed to stand at room temperatures for 20 minutes and then concentrated to one-fifth volume by vacuum distillation. Insoluble solids are filtered OE and taken up in 50 parts of ethyl acetate. Concentration of the ethyl acetate solution to one-half volume by vacuum distillation results in precipitation of hydrated 17-hydroxy- 3-oxo-l7a-pregn-4-ene-7u,2l-dicarboxylic acid 'y-lactone, which is isolated by filtration. Additional product is isolable by extracting the filtrate with aqueous 5% potassium bicarbonate, acidifying the extract with 3% hydrochloric acid, again concentrating by vacuum distillation until precipitation of product occurs, and filtering. Water of crystallization is removed from the hydrate thus produced by heating in vacuo at around 80, aifording anhydrous product melting at 266270 and having the formula to H30 --OOOH EXAMPLE 5 Potassium Zl-carboxy-l7-hydroxy-3-oxo-l7a-pregn-4- ene-h-carboxylate 'y-lactone A solution of 412 parts of 17-hydroxy-3-oxo-17a-pregn- 4-ene-7 a,21-dicarboxylic acid 'y-lactone monohydrate and 100 parts of potassium bicarbonate in a mixture of 7900 parts of methanol and 12,000 parts of water is stirred under nitrogen at room temperatures overnight, then heated at 40 for 30 minutes. Substantially all of the liquids are thereupon removed by vacuum distillation, leaving a yellow oil which is azetropically dried by distilling ethanol therefrom. Trituration of the dried oil with ethyl acetate aifords potassium 2l-carboxy-17-hydroxy-3-oxo-l7u-pregnl -eneflwcarboxylate 'rlactone as a colorless solid which is isolated by filtration and dried in air. The product has the formula g l \V ,1

Dip otassium l7-hydroxy-3-oxo-l 7a-pregn-4-ene-7a,2 l-

dicarboxylate dihydrate A solution of 106 parts of l7-hydroxy-3-oxo-17a-pregn- 4-ene-7u,2 l-dicarboxylic acid 'y-lactone monohydrate in 730 parts of aqueous 4% potassium hydroxide is diluted with 2 volumes of water. The resultant solution is heated at 90-95 for 30 minutes, then stripped of water by vacuum distillation. The residue is extracted with 2-propanol. The propanol solution is filtered and, in turn, stripped of solvent by vacuum distillation, leaving a yellow powder which is dried in vacuo at 65 for 24 hours, then redissolved in 10,000 parts of hot Z-propanol. This solution is filtered, and the filtrate is concentrated to one-fourth volume by vacuum distillation. The precipitate thrown down as the concentrate cools is dipotassium 17-hydroxy- 3 oxo 17oz pregn-4-ene-7a,2l-dicarboxylate dihydrate, which is filtered oil and dried in air. Water of crystallization can be removed from the dihydrate by heating in vacuo at around 80. The dihydrate has the formula H3O I urricane OK 8 EXAMPLE 7 17-hydroxy-3-oxo-l7a-pregn-4-ene-7a,2l-dicarboxylic acid To a solution of 2 parts of dipotassium l7-hydroxy-3- oxo-17a-pregn4-ene-7u,2l-dicarboxylate dihydrate in parts of water is added 10 parts of 5% hydrochloric acid. The colorless precipitate which results is filtered 01f, washed with water, and dried in air. The product thus isolated has the formula O --C O OH EXAMPLE 8 7a-ethylthiocarbonyl-l7-hydroxy-3-oxo-l7a-pregn- 4ene-2l-carboxylic acid -y-lactone To a solution of 6 parts of l7-hydroxy 3 oxo 17apregn 4 ene-7a,21-dicarboxylic acid 'y-lactone monohydrate in approximately 15 parts of triethylamine and parts of chloroform maintained at 0 is added approximately 7 parts of ethyl chloroformate. The resultant solution is allowed to warm to room temperature and stirred overnight, whereupon solvents are removed by vacuum distillation. The brown gummy residue is redissolved in a mixture of approximately 4 parts of triethylamine and 150 parts of chloroform. To this solution is added 5 parts of ethanethiol. The resultant solution is stirred at room temperatures overnight. Solvents are then again removed by vacuum distillation, and the residue is taken up in chloroform. The chloroform solution is washed with approximately 3% hydrochloric acid and then with water, dried over sodium sulfate, and stripped of chloroform by vacuum distillation. The residue is chromatographed on dry silica gel, using 12% ethyl acetate in benzene as developing solvent. Upon evaporation of the solvent, 7aethylthiocarbonyl-17-hydroxy-3-oxo-17ot-pregn 4 ene- 2l-carboxylic acid 'y-lactone melting at 202204 is obtained. The product has the formula EXAMPLE 9 17-hydroxy-3-oxo-7u-propylthiocarbonyl-l7a-pregn-4- ene-Zl-carhoxylic acid -lactone Substitution of 5 parts of propanethiol for the ethanethiol called for in Example 8 aifords, by the procedure there detailed, 17 hydroxy-3-oxo-7u-propylthiocarbonyl- 17ot-pregn-4-ene-2l-canboxylic acid 'y-lactone.

EXAMPLE l0 l7-hydroxy-7a-methoxycarbonyl-3-oxo-17u-pregna-L4- diene-Zl-carboxylate -lactone tetartohydrate A solution of 14 parts of 17-hydroxy-7a-methoxycarbonyl-3-oxo-17a-pregn-4-ene-2l-carboxylic acid 'y-lactone and 11 parts of dichlorodicyanobenzoquinone in 1800 parts of benzene is heated at the boiling point under reflux with stirring in a nitrogen atmosphere for 20 hours, then diluted with approximately 1000 parts of ether and filtered. The filtrate is washed with aqueous 2% sodium sulfite until the washes are colorless, whereupon it is washed with water, dried over sodium sulfate and magnesium sulfate, and stripped of solvent by vacuum distillation. The resdual yellow oil is chromatographed on dry silica gel, using 12% ethyl acetate in benzene as developing solvent. Upon evaporation of the solvent and recrystallization of the residue from ether, 17-hydroxy-7u-methoxycarbonyl-B-oxo-17a-pregna-1,4-diene-2l carboxylic acid -y-lactone tetartohydrate melting at 217-222 is obtained. Water of crystallization can be removed by heating in vacuo at around 80. The tetartohydrate has the formula --CO OCH: M1120 EXAMPLE 11 17-hydroxy-3-oxo-17a-pregna-1,4-diene-7u,2ldicarboxylic acid y-lactone A solution of 1 part of 17-hydroxy 7a methoxycarbonyl-3-oxo-17a-pregna-1,4-diene 21 carboxylic acid -lactone tetartohydrate and 12 parts of aqueous 5% potassium hydroxide in 20 parts of methanol is heated at the boiling point under reflux for 6 hours. Methanol is thereupon removed by vacuum distillation; and the aqueous residue is diluted with 25 parts of acetone, adjusted to pH 4 with 3% hydrochloric acid, and allowed to stand at room temperature for 20 minutes. Sufiicient liquid is then removed by vacuum distillation to bring about precipitation. The precipitate is filtered oh and taken up in ethyl acetate. The ethyl acetate solution is extracted with aqueous 5% potassium bicarbonate. The bicarbonate extract is acidified and then concentrated by vacuum distillation. The residual yellow oil is chromatographed on dry precipitate which forms on standing is filtered 011 and dried in air. The product thus isolated is 17-hydroxy-3- oxo 170: pregna 1,4 diene 7m,21 dicarboxylic acid 'y-lactone.

EXAMPLE 12 Dipotassium 17-hydroxy-3-oxo-17a-pregna-1,4- diene-7a,21-dicarboxylate A solution of 100 parts of 17-hydroxy- 3 oxo -17apregna-1,4-diene 711,21 dicarboxylic acid 'y-lactone and 744 parts of aqueous 4% potassium hydroxide in 4000 parts of methanol is heated at the boiling point under reflux for 2 hours. Substantially all of the liquids are removed from the resultant solution by vacuum distillation, and the yellow gummy residue is further dried azeotropically by distilling ethanol therefrom. The colorless residue thus obtained is recrystallized from ethyl acetate to give dipotassium 17-hydroXy-3-oxo-17u-pregna-1,4-diene- 7a,21-dicarboxylate.

EXAMPLE l3 17-hydroxy-3-oxo-17a-pregna-1,4-diene-7m,21- dicarboxylic acid Substitution of 2 parts of dipotassium 17-hydroxy-3- oxo-17a-pregna-1,4-diene-7u,2-1-dicarboxylate for the dipotassium 17-hydroxy-3-oxo-17a-pregn-4-ene-7a,2l-dicarboxylate dihydrate called for in Example 7 aifords, by the procedures there detailed, 17-hydroxy-3-oxo-17a-pregna- 1,4-diene-7a,2 l-dicarboxylic acid.

1'0 EXAMPLE 14 7a-ethoxycarbonyl-17-hydroxy-3-oxo-17a-pregn-4-ene-21- carboxylic acid -lactone and 7fl-epimer To 18 parts of sodium metal is added 840 parts of absolute ethanol at a rate such that rapid refluxing is maintained. When the addition is complete, refluxing is continued for 3 hours via external heating, whereupon 14,000 parts of ethanol followed by approximately 20 parts of 4a,7a-carbonyl-5-cyano-7-hydroxy-3-oxo-55,17apregnane-ZI-carboxylic acid -y-lactone is introduced. The resultant solution is heated at the boiling point under reflux with stirring in a nitrogen atmosphere for 21 hours, then cooled and diluted with 10 volumes of water. Solvent is removed by vacuum distillation. An equal volume of acetone is added to the residue, followed by sufficient 3% hydrochloric acid to induce acidity. The resultant mixture is stripped of acetone by vacuum distillation, and the residual aqueous gum is extracted with dichloromethane. The dichloromethane extract is dried over sodium sulfate and magnesium sulfate, whereupon solvent is distilled off in vacuo and the residual yellow foam chromatographed on dry silica gel, using 10% ethyl acetate in benzene as developing solvent. Upon evaporation of solvent and recrystallization of the residue from petroleum solvent boiling in the range 95-127", 7a-ethoxycarbonyl 17 hydroxy-3-oxo-17a-pregn-4-ene-2 l-carboxylic acid 'y-lactone melting at 143-145 is obtained.

The mother liquor is chromatographed on silica gel, using benzene and mixtures thereof with increasing amounts of ethyl acetate as developing solvents. From an eluate comprising 15% ethyl acetate in benzene, on evaporation of solvent, 7/3-ethoXycarbonyl-l7-hydroxy-3- oxo-l7ct-pregn-4-ene-21-carboxylic acid 'y-lactone is obtained as the residue.

EXAMPLE l5 17-hydroxy-7a-isopropoxycarbonyl-3-oxo- 1 7a-p1'6 gn-4- ene-Zl-carboxylic acid 'y-lactone To a solution of parts of 17-hydroxy-3-oxo-17apregn4-ene-7a,21-dicarboxylic acid 'y-lactone monohydrate and 20 parts of 4-methylmorpholine in 600 parts of tetrahydrofuran at 15 under nitrogen is added, with stirring, 28 parts of isobutyl chloroformate. A white precipitate is thrown down. After 5 minutes, 640 parts of 2-propanol is introduced; and the resultant mixture is filtered in a nitrogen atmosphere. The filtrate is stripped of solvent by vacuum distillation, and the oily brown residue is taken up in 1560 parts of 2-propanol. This solution is heated at the boiling point under reflux for 6 hours, whereupon 1 part of imidazole is introduced. Boiling under reflux is resumed for a period of 18 hours, at which point 2000 parts of water is introduced. The resultant mixture is boiled under reflux for 35 hours, then freed of solvent by vacuum distillation. The gummy residue is extracted with ethyl acetate. The extract is thoroughly washed with aqueous 5% potassium bicarbonate and then with water, dried over sodium sulfate and magnesium sulfate, and stripped of solvent by vacuum distillation. The residual brown oil is chromatographed on dry silica gel, using 1% ethanol in chloroform as developing solvent. Upon evaporation of the solvent and recrystallization of the residue from ether, 17-hydroxy 7a isopropoxycarbonyl-3-oxo-l7u-pregn-4- ene-21-carboxylic acid 'y-lactone melting at 181-183 and further characterized by a specific rotation of +16.12 is obtained.

EXAMPLE 16 (A) Anhydride of 17-hydroxy-3-oxo-17a-pregn-4-ene-7a, 21-dicarboxylic acid 'y-lactone with isobutoxyformic acid To a solution of 221 parts of 17-hydroxy-3-oxo-17apregn-4-ene-7zx,2l-dicarboxylic acid 'y-lactone and 50 parts of 4-methylmorpholine in 2250 parts of tetrahydrofuran at 10 under nitrogen is added, with stirring, 65 parts of isobutyl chloroformate. A white precipitate forms immediately. Stirring is continued for 10 minutes, Whereupon the reaction mixture is filtered; and the filtrate is stripped of solvent by vacuum distillation. The residual yellow oil, on chilling overnight, crystallizes. The material thus isolated is the anhydride of 17-hydroxy-3-oxo- 17a-pregn-4-ene-7u,2l-dicarboxylic acid 'y-lactone with isobutoxyformic acid which, recrystallized from hexane, melts at 144146. The product has the formula "00200 014 CH(CH )3 (B) 17-hydroxy-7a-isobutoxycarbonyl-3-oxo-17x-pregn-4- ene-2l-carboxylic acid 'y-lactone A solution of 49 parts of the anhydride of 17-hydroxy- 3-oxo-l7a-pregn4-ene-7a,21-dicarboxylic acid 'y-lactone with isobutoxyformic acid in 800 parts of isobutyl alcohol is heated at 90-95 under nitrogen for 12 hours. Solvent is removed by vacuum distillation, whereupon the residue crystallizes. Recrystallization from methanol affords 17- hydroxy 7a isobutoxycarbony1-3-oxo-l7a-pregn-4-ene- 21-carboxylic acid 'y-lactone melting at 200-202 and having a specific rotation in chloroform solution of +l7.40.

' EXAMPLE l7 17-hydroxy-7a-isohexyloxycarbonyl-3 -oxo-l7a-pregn-4- ene-Zl-carboxylic acid 'y-lactone To a solution of 80 parts of 17-hydroxy-3-oxo-17apregn-4-ene-7a,21-dicarboxylic acid 'y-lactone and 20 parts of 4-methylmorpholine in 600 parts of tetrahydrofuran at l5 under nitrogen is added, with stirring, 28 parts of isobutyl chloroformate. Precipitation occurs. Stirring is continued for 5 minutes, whereupon 640 parts of 2- propanol is introduced. The resultant mixture is filtered under nitrogen, and the filtrate is stripped of solvent by vacuum distillation. The residue is taken up in 1560 parts of 4-methyl-1-pentanol, and this solution is heated at the boiling point under reflux for 3 hours. Approximately 2000 parts of water is added at this point and boiling under reflux then resumed for a further 35 hours. Solvent is thereupon removed by vacuum distillation, and the residue is extracted with ethyl acetate. The ethyl acetate extract is consecutively washed with aqueous 5% potassium bicarbonate and water, dried over sodium sulfate and magnesium sulfate, and finally stripped of solvent by vacuum distillation. The residue is chromatographed on dry silica gel, using 3 /2% ethyl acetate in chloroform as developing solvent. On evaporation of solvent and recrystallization of the residue from ether, colorless crystalline 17-hydroxy-7a-isohexyloxycarbonyl- 3-oxo-l7a-pregn-4-ene-2l-carboxylic acid -y-lactone melting at 118-120 and with a specific rotation of +20.90 is obtained.

EXAMPLE 18 Potassium 7m ethoxycarbonyl 17-hydroxy-3-oxo-17apregn-4-ene-2l-carboxylate monohydrate A solution of 43 parts of 7a-ethoxycarbonyl-l7-hydroxy-3-oxo-l7a-pregn-4-ene-2l-carboxylic acid 'y-lactone and 135 parts of aqueous 4% potassium hydroxide in 2000 parts of ethanol, protected by a nitrogen atmosphere, is allowed to stand overnight at room temperatures and then heated at 50-55 for 20 minutes. Solvent is thereupon removed by vacuum distillation and the residue triturated with ethyl acetate. Insoluble solids are separated by filtration and dried in air. The product thus isolated is potassium 7a ethoxycarbonyl 17 hydroxy-Ii-oxo-lhpregn-4-ene-2l-carboxylate monohydrate. The precipitate is isolated by filtration and dried in air. Water of crystallization is removed by heating in vacuo at around EXAMPLE 19 Potassium 17-hydroxy-7a-isopropoxycarbonyl-3-oxo-17apregn-4-ene-2l-carboxylate EXAMPLE 20 Sodium 17 hydroxy 7u-methoxycarbonyl-3-oxo-17apregn-4-ene-2l-carboxylate To a solution of 200 parts of 17-hydroxy-h-methoxycarbonyl-3-oxo-l7a-pregn-4-ene-2l-carboxylic acid 'y-lactone in 7000 parts of methanol under nitrogen is added, with stirring, 397 parts of aqueous 5% sodium hydroxide. The resultant mixture is stirred at 40 for 2 hours, then stripped of solvent by vacuum distillation. The residue is Washed by slurrying with ethyl acetate and dried in air. The product thus isolated is sodium 17-hydroxy-7a-methoxycarbonyl-3-oxo-17u-pregn-4-ene-2l-carboxylate.

EXAMPLE 21 Calcium bis[ 17-hydroxy-7m methoxycarbonyl-3-oxo-17apregn-4-ene-2l-carboxylate] A mixture of 200 parts of 17-hydroxy-7a-methoxycarbonyl-3-oxo-17u-pregn-4-ene-2l-carboxylic acid, 19 parts of calcium hydroxide, and 4000 parts of methanol is stirred at 40 under nitrogen for 2 hours. Solvent is then removed by vacuum distillation, and the residue is recrystallized from ethyl acetate. The product thus isolated is clacium bis[l7-hydroxy-7m-methoxycarbonyl-3-oxo-l7u pregn-4- ene-ZI-carboxylate] EXAMPLE 22 Ammonium 17-hydroxy-7u methoxycarbonyl-3-oxo-17apregn-4-ene-2l-carboxylate To 20 parts of 2-propanol, saturated with ammonia, is added 1 part of 17-hydroxy-7a-methoxycarbonyl-3-oxo- 17m-pregn-4-ene-2l-carboxylic acid. The resulting mixture is allowed to stand at room temperatures for 24 hours, at which point solvent is removed by vacuum distillation. The residue is washed with ethyl acetate and dried in air. The product thus isolated is ammonium l7-hydroxy-7amethoxycarbonyl-3-oxo-l7ot-pregn-4-ene-2l-carboxylate.

EXAMPLE 23 Sodium 2l-carboxy-17-hydroxy-3 oxo-17u-pregn-4-ene- 7a-carboxylate 'y-lactone Substitution of 84 parts of sodium bicarbonate for the potassium bicarbonate called for in Example 5 affords, by the procedure there detailed, sodium 21-carboxy-17-hydroxy-3-oxo-17a-pregn-4-ene-7a-carb0xylate 'y-lactone.

EXAMPLE 24 Calcium bis[21-carboxy-17-hydroxy-3-oxo 17a-pregn-4- ene-h-carboxylate -lactone] A mixture of parts of 17-hydroxy-3-oxo-Hot-pregn- 4-ene-7a,21-dicarboxylic acid 'y-lactone monohydrate, 9 parts of calcium hydroxide, and 5000 parts of 2-propanol is stirred at 40 under nitrogen for 2 hours. The resultant mixture is stripped of solvent by vacuum distillation, and the residue is slurried with hot ethyl acetate. The insoluble solids isolated by filtration are calcium bis[2l-carboxy-17- hydroxy-3-oxo-17m-pregn-4-ene-7a-carboxylate 'y-lactone].

EXAMPLE 25 Ammonium 2l-carboxy-17-hydroxy-3 oxo-17a-pregn-4- ene-h-carboxylate -lactone Substitution of 1 part of l7-hydroxy-3-oxo-l7a-pregn- 4-ene-7a,21-dicarboxylic acid 'y-lactone monohydrate for the l7-hydroxy-7a-methoxycarbonyl 3-oxo-17a-pregn-4- ene-ZI-carboxylic acid called for in Example 21 affords, by the procedure there detailed, ammonium 21-carboxy- 17-hydroxy-3-oxo-17a-pregn-4-ene-7u carboxylate 'y-lactone.

What is claimed is:

1. A compound of the formula HaC OH 'CHQCHI 00B T k/ o=L/ lvwc 0 $11 HsC -lower alkyl wherein R represents hydrogen, alkali metal, Ca/2, ammonium, or lower alkyl; R represents hydrogen, alkali metal, Ca/2 or ammonium; the dotted line signifies the locus of an optional double bond; and the wavy line designates alpha or beta configuration.

2. A compound according to claim 1 which is 17-hydroxy 7B methoxycarbonyl-3-oxo-l7u-pregn4-ene-2 lcarboxylic acid 'y-lactone.

3. A compound according to claim 1 having the formula -- C O O-lower alkyl wherein the dotted line signifies the locus of an optional double bond.

7. A compound according to claim 1 which is 17-hydroxy-h-methoxycarbonyl 3 oxo-17a-pregna-1,4-diene- 21-carboxylic acid 'y-lactone.

8. A compound according to claim 1 having the formula O C O O-lower alkyl 9. A compound according to claim 1 which is 17-hydroxy-h-methoxycarbonyl 3 oxo-17a-pregn-4-ene21- carboxylic acid v-lactone.

10. A compound according to claim 1 which is 17-hydroXy-7a-isopropoxycarbonyl 3 oxo 17a-pregn-4-ene- 21-carboxylic acid -lactone.

11. A compound according to claim 1 having the formula 0- --C 0 S-lower alkyl wherein the dotted line signifies the locus of an optional double bond.

12. A compound according to claim 1 which is 7ozethylthiocarbonyl 17 hydroxy 3-oxo-17a-pregn-4-ene- ZI-carboxylic acid 'y-lactone.

13. A compound according to claim 1 having the formula --COOR" --C O O-lower alkyl wherein R represents hydrogen, alkali metal, Ca/ 2 or ammonium.

16. A compound according to claim 1 which is potassium 1'7-hydroxy-7a-ethoxycarbonyl 3 oXo-17a-pregn- 4-ene-21-carhoxylate.

17. A compound according to claim 1 which is potassium 17-hydroxy-h-isopropoxycarbonyl 3 oxo 17apregn- Lene-Zl-carboxylate.

18. 70:,4 aminomethylidyne 5 cyano-l7-hydroxy-3- oxo-Sfl,17a-pregnane-2l-carboxylic acid 'y-lactone.

19. flu-carbonyl S-cyano-17-hydroxy-3-oxo-SBJ7apregnane-Zl-carboxylic acid 'y-lactone.

20. Anhydride of 17-hydroxy-3-oxo-17m-pregn-4-ene- 7a,21-dicarboxylic acid 'y-lactone with isobutoxy-formic acid.

21. A compound according to claim 1 which is potassium 17-hydroxy 7a-methoxycarbonyl-3-oxo-17a-pregn- 4-ene-21-carboxylate.

No references cited.

ELBERT L. ROBERTS, Primary Examiner U.S. Cl. X.R.

' UNITED STATES PATENT OFFICCEYE Page 1 r 2 CERTIFICATE OF CORRECTION Patent 2.787 .296 Dated January 22 197a Inv lX Richard M. Weier It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, first and second formulae; column 2, first formula; column 1, first formula; column 5, first and second formulae; column 7, first and second formulae; column 8, second formula; column 9, first formula; column 11, first formula column 13, first, third, and fourth formulae; and column 1 first, second and third formulae;

NH H H Q/ should be v l/ Column 2, line 57, "hydroxy-l'ia" should be hydroxy- 70L-.

Column 6, line 13, l-ene 2l-carboxylat9" should be l-ene-2l-carboxylate Column 6, first formula,

H C I! I C Should be Column 6, line 38, "methoxycarbondyl" should be methoxycarbonyl Column 7, line 26, "azetropically" should be azeotropically Column 7, line 57, "at 65" should be at 65 RM PO-iOSO (10-69) USCOMM-DC 60376-P69 w u.s. covsnnuim' PRINTING orncs: I909 o-ais-au V UNITED STATES PATENT OFFICE P 2 2 Patent No. 3,787,396 Dated Januery 22, 197 1 Inv n d-$0 Richard M. weier It is certified that error appears in the above-identified patent and that saidLetters Patent are hereby corrected as shown below:

Column 9, line 5, "resdual" should be residual Column 9, lines IN-H5, "distillation, The residual yellow oil is ch-romatographed on dry" should be distillation to the point of incipient precipitation. The colorless ColumnlO, line 9, "7-hydroxy" should-be l'hhydroxy Colunin l2, line 1M,- "clacium" .sh ould b--'- calcium Signed and sealed this 20th day of Au ust 197 (SEAL) Attest:

McCOY M. GIBSON, JR. 7 C; MARSHALL DANN Attesting Officer Commissioner of Patents FORM PO-105O (10-59) USCOMM-DC scan-poo U.S. GOVERNMENT PRINTING OFFICE: I!" O-3i6-33l 

